His name is Harry Strickland, and he is a character from the Song of Ice and Fire novel series, which the Game of Thrones television show is based off. In the books, he's the leader of the Golden Company army of sellswords. And that's exactly who Cersei has hired to help win the war for the Lannisters.

Vanity Fair reports that spying fans have even deduced identity of that actor playing Harry Strickland. His name is Marc Rissman, and his previous acting credits include swinging a sword on Viking drama The Last Kingdom. He also has a serious beard so clearly, he's qualified to join the cast of Game of Thrones.

The season 7 finale, The Dragon and the Wolf, left us wondering if Jaime finally left Cersei for good on that horse. Given that Rissmann is kind of, shall we say, fine as hell, we're wondering this means that he will also make overtures to Cersei's heart. He'll have a tough competition in the form of Euron Greyjoy, who still thinks he can pirate his way to the Iron Throne. Cersei seems thoroughly uninterested in the boorish Greyjoy, so we're curious to see if she falls for the leader of her new army. It would be the most reasonable thing she's done in the entire show.